AbstractLongevity, host preference, length of life stages and the number of offspring of Habrobraconhebetor were evaluated on the host larvae of Ephestia kuehniella treated with lethal and sub-lethal doses of Bacillus thuringiensis Experiments were conducted in a completely randomized design under laboratory condition. The number of eggs decreased from 3.9 in control to 1.4 and 2.7 in lethal and sub-lethal doses, respectively. By reducing the number of parasitoid offspring from 3.7 in control to 0.6 and 1.2 in lethal and sub-lethal doses, also the adult parasitoid longevity decreased from 15.6 days in control to 12.3 and 13.7 days in lethal and sub-lethal doses, respectively. In the lethal dose of Bt treatment, duration of embryonic and larval stages of the wasp showed a significant increase compared to control, but pupal stage duration decreased in both lethal and sub-lethal doses of Bt treatment. Generally, by reducing the usage dose of Bt and avoiding its application during the critical stages of parasitoid life, the efficiency of their use in integrated pest management can be improved.

Baur ME and Boethel DJ, 2003. Effect of Bt-cotton expressing Cry1A (c) on the survival and fecundity of two hymenopteran parasitoids (Braconidae, Encyrtidae) in the laboratory. Biological Control 26: 325-332.